The ocean makes up 70% of our planet and coral reefs make up only 1% of our oceans. Yet, they are responsible for 25%–40% of all marine life.
Not only are they responsible for marine but they represent an economic value of $36 BILLION and they shield coasts from powerful waves which allow us to live there.
Over the past decade climate change has been a huge issue and this is due to the increased amount of CO2 in the atmosphere. As a result of global warming, coral bleaching or the death of corals have increased exponentially. This is largely due to two factors:
- Global warming
- Ocean acidification
How does Global Warming Affect Coral Bleaching?
The bright colours that characterize corals do not actually come from the corals themselves but the algae that occupy the corals. These algae have a symbiosis relationship with the coral. They use photosynthesis to produce sugar and oxygen that the corals need and the coral supplies algae with CO2.
Increases in temperature is killing these algae and that is what we see when we see a coral bleaching event. The corals are technically still alive even though they have no colour, but they will not survive for long without oxygen and sugar.
How does Ocean Acidification Affect Corals?
Carbon dioxide reacts with water to form carbonic acid. Carbonic acid is a diprotic acid, meaning that it will dissociate twice to release two hydrogen ions instead of one, like a monoprotic acid. Carbonic acid is also a strong acid, meaning it will dissociate 100% in water.
Such an increase in hydrogen ions means a higher concentration of hydrogen ions, thus resulting in a lower pH or making the ocean more acidic. The net products of this reaction are two hydrogen ions and a carbonate ion.
Calcium carbonate is produced by corals to maintain hard structure, it is also present in most shellfish. An increase in hydrogen ions mean that these ions want to react with carbonate to create bicarbonate. Therefore, these ions are competing with these creatures for carbonate. As a result, the shells of shellfish and the structure of corals with disintegrate.
DON’T WORRY, even though we are in an emergency situation there are many people looking for solutions. One of which is gene editing
You might have heard of this technology on the news a lot lately.
The use of this technology on humans is still in debate, however, the use of this tech in trying to save the world is widely encouraged.
Before we talk about how CRISPR can be used in corals, we must understand how it works. CRISPR was found in bacteria as a mechanism to fend off viral infections, however, scientists have discovered a way to leverage this discovery and program the CAS9 protein to edit any gene. CRISPR essentially programs the CAS9 molecule using a gRNA(guide RNA) and it will search the DNA of a genome, find the piece of DNA that matches the gRNA and cut that part of the genome. DNA, then, has their own repair system to repair the part that was cut, turning off that part of the gene.
Application to Corals
Using CRISPR-CAS9, we can then turn off certain genes that make the corals more susceptible to respond negatively to coral bleaching events and that make corals more resilient to having less calcium carbonate.
- Corals are extremely important to marine and coastal life. Coral numbers have decreased a large amount in the past decade due to global warming and ocean acidification.
- CRISPR-CAS9 is a gene editing tool that could be a solution to the extreme loss of corals
Hi! My name is Rosa and recently I have been researching gene editing. If you have any feedback for my article please don’t be afraid to comment. It would be greatly appreciated! You can contact me at: